There’s a significant difference between what humans perceive as complex, and what is complex for computers (especially limited computers like embedded microcontrollers or DSP chips) to do.
Some of the things you may be perceiving as “complex” new features—e.g. the new Euclidean sequencer mode—may actually consume very little resources compared to an LFO. An LFO has to be computed in real time for every tick of the sampling rate of the machine, as well as its effects on whatever it’s modulating. Computing a Euclidean sequence requires a much lower time granularity, and moreover you can handle it even more efficiently by pre-generating a truth table of all possible permutations of the available Euclidean parameters, and then just doing a simple data lookup from the table when you need a pattern. Then all you need is enough memory to store the table, which can be quite tiny, and frees up CPU cycles for other things.
That brings us to another reality: embedded systems like this have multiple kinds of resources—CPU, memory, the bandwidth of the memory circuits, the processing power and memory of various subsystems such as DACs and USB, etc. When a hardware system like this gets initially designed, there’s typically some advance planning for future growth in firmware updates, but the designers can’t always anticipate what updates will be needed and what resources they will require. You may think you’ve given yourself enough room to do everything the users might ask for after 1.0, but sometimes the users surprise you by wanting different things, and you have to adapt within the limitations you have already set yourself. It only takes exceeding the limit of any one of these resources for a feature to become technically infeasible—e.g. you may have tons of free memory but be all out of CPU cycles, or bandwidth to communicate with the memory.
TL;DR—when the developers of embedded systems tell me a feature is technically infeasible, I am inclined to believe them. It may seem like a simple task to me, but they are the experts in the limitations of the specific system they have designed.